Epidermal and hypodermal characteristics in North American Cactoideae (Cactaceae)

Abstract

Dermal and hypodermal anatomical features of 70 species representing 21 genera of North American Cactoideae were studied. Results show that all species examined have parallelocytic stomata and anticlinal wall surface varies from straight to undulate. Cuticle thickness is mostly narrow (1-10 m m) contrary to the general opinion that cuticle is thick in most cacti; however, few species such as Ariocarpus fissuratus and several species of Pachycereus show a distinctive thick cuticle. More than 80% of the species studied have a single-layered epidermis. Papillae occur in eight species belonging to four genera. Notable papillae are a feature shared by all members of Peniocereus subg. Peniocereus . Other species show a bullate surface produced by irregular patches of secondary epidermal cell divisions. Commonly, the hypodermis is composed of more than two cell layers with distinctive collenchymatous walls as reported in many South American species. Silica bodies, prismatic crystals, druses, sphaerocrystals, and tannins are the most common cellular inclusions that distinguish several genera and appear to have taxonomic value. However, a more thorough search in species of Cephalocereus , Coryphantha , Echinocereus , Mammillaria , Neobuxbaumia , Pilosocereus , and Turbinicarpus is needed to support the previous assertion.

Micromorphology and Phytochemical Screening of Opuntia Littoralis Englem. Cladodes

“…In many Opuntioideae and Cactoideae, hypodermis cells have such thick hard walls that microtoming them is almost impossible and many contain druses in one or several layers of hypodermis. Similar results were recorded by many researchers (Conde, 1975;Mauseth and Ross, 1988;Mauseth, 1996Mauseth, , 1999Mauseth and Kiesling, 1997;Plemons-Rodriguez, 1998 andLoza-Cornejo andTerrazas, 2003). According to Martin and Juniper (1970), the hypodermis helps to protect the inner tissues from the outer extreme conditions.…”

Solar radiation as a factor in the evolution of scleromorphic leaf anatomy in Proteaceae

“…Furthermore, the thick cuticles observed here are much thicker than those of many xerophytes. For example, most North American Cactoideae (the main group of cacti) have cuticles 5 m thick or less (Loza-Cornejo and Terrazas, 2003), and five of six disparate South African arid species sampled by Jordaan and Kruger (1998) had cuticles less than 2 m thick. The hypodermal tissues described here are unlikely to reduce water loss be-cause these structures are all heavily pitted.…”

Compositional and transcriptomic analysis associated with cuticle lipid production on rosette and inflorescence stem leaves in the extremophyte Thellungiella salsuginea

“…The different plant organs can produce quite different cuticle types, and this can vary significantly in different growth stages (Li‐Beisson et al 2013). It is generally presumed that these differences have an important adaptive significance, and it should not be overlooked that many extremophytes adapted to arid and saline environments, such as T. salsuginea , produce relatively high amounts of cuticle lipids on their surfaces (relative to more mesophytic plants), and these extremophile species sometimes in fact produce extremely thick and high‐weight cuticles (Loza‐Cornejo and Terrazas , Kosma and Jenks ). Furthermore, our observation that the stem leaf cuticles are much more robust than rosette leaf cuticles may indicate an optimized phenotype that aids T. salsuginea 's survival in the extreme environments from where it is native.…”